Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
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assuming there was no noise before the repair, I see why you question this. the most obvious thing I can think of is that they may have dropped something down into a spark plug hole during the repair. the only way to verify is to remove the heads and inspect. if you take it to another shop that has a boroscope, they could remove the plugs again and look into the cylinders and check.